George Boole

and the Truth Tables

Test Corrections & Makeup

Tuesday

(Today)

Wednesday

Thursday

Friday

Corrections

Corrections

Corrections

Makeup Test

Corrections

Pass Makeup Test?

Grade goes up to 70

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Get an A on Makeup Test?

Get half point back!

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Makeup test will not cause grade to go down

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Must do corrections in tutorials in order to take makeup test

Elementary Algebra

Operators

Addition +

Subtraction -

Multiplication *

Division /

Equality =

Values

Integers (… -2, -1, 0, 1, 2 …),

Real Numbers,

Irrational Numbers…

​

Boolean Algebra

Operators

AND &&

OR ||

NOT !

NOT EQUALS !=

EQUALS ==

Values

true

false

Expressions

true && false

A || B

var == false

AND

If A and B are both true, then A && B evaluates to true,

otherwise it is false.

A 🡪 it is raining

B 🡪 it is Monday

​

if A && B then wear a green hat

Truth Table

Enumerating Boolean Values

How many different values can you store in 1 Boolean variable?

Enumerating Boolean Values

How many different values can you store in 1 Boolean variable?

Enumerating Boolean Values

How many different values can you store in 2 Boolean variables?

​

Enumerating Boolean Values

How many different values can you store in 2 Boolean variables?

​

When A is false, B could be false or true.

​

​

​

​

​

When A is true, B could be false or true

Enumerating Boolean Values

How many different values can you store in 2 Boolean variables?

​

Enumerating Boolean Values

How many different values can you store in 3 Boolean variables?

​

OR

If either A or B is true, then A || B evaluates to true,

otherwise it is false.

A 🡪 it is raining

B 🡪 it is Monday

​

if A || B then wear a green hat

Equals

If A is the same as B, then A == B evaluates to true,

otherwise it is false.

If A is not the same as B, then A != B evaluates to true,

otherwise it is false.

​

AND and OR

Not

If A is true, then !A evaluates to false,

otherwise it is true.

Boolean Algebra

&& Both values are true (TT)

|| Either value is true (FT, TF, TT)

== Both values are the same (TT, FF)

Boolean Operators and if-statements

if( a )

{

if( b )

{

​

​

​

}

}

if( a && b )

{

​

​

​

}

Boolean Operators and if-statements

if( a )

{

​

​

}

else if( b )

{

​

​

}

if( a || b )

{

​

​

}

Boolean Operators and if-statements

if( a )

{

}

else

{

​

​

​

}

if( !a )

{

​

​

​

}

FUNSHEET

Mayflower, detecting a key hold

What does this do?

​

if( Mayflower.isKeyDown(Keyboard.KEY_SPACE) )

{

actor.move(1);

}

Mayflower, detecting a key hold

What does this do?

​

if( Mayflower.isKeyDown(Keyboard.KEY_SPACE) )

{

actor.move(1);

}

wasKeyDown?

​

​

if( Mayflower.wasKeyDown(Keyboard.KEY_SPACE) )

{

actor.move(1);

}

Write the condition for the if-statement so that it moves the actor 1 pixel only if the SPACE key was pressed for the first time this frame.

if( ??? )

{

actor.move(1);

}

​

Mayflower.isKeyDown( Keyboard.KEY_SPACE)

Mayflower.wasKeyDown( Keyboard.KEY_SPACE)

​

&& || ! == !=

​

Only moves in this frame

Funtivity!

If the key is pressed now and it wasn’t pressed last update, then…

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if( Mayflower.isKeyDown(Keyboard.KEY_SPACE) &&

!Mayflower.wasKeyDown(Keyboard.KEY_SPACE)

)

{

actor.move(1);

}

Mayflower Collision Checking

isTouching( Blah.class )

This method can be called inside the act method of an Actor.

It evaluates to true if that actor is touching any actor of the specified type (Blah)

​

public class Sonic

{

public void act()

{

if( isTouching(Ring.class) )

{

score++;

}

}

}

Sonic

Ring

Lab 2.1 Frogger

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Have you clicked the �“Sign up for Test” button?

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Deadline: October 4^th!